China's carbon-monitoring satellites are expected to be ready by May, having been in development for four years at the Changchun Institute of Optics and Fine Mechanics and Physics, which is part of China's Academy of Sciences.

According to an earlier report by the China Meteorological Administration, the precision of the satellites' monitoring will be greater than 4 parts per million (ppm) and will run in conjunction with ground-based data processing and verification systems.

At present, no launch date or other details have been shared, but the development signifies a new level of commitment by China to measure its emissions accurately.

Conventional greenhouse gas emissions are calculated off reported levels of fossil fuel usage, but this method is far from perfect. Not only is it limited to tracking industrial contributions to global warming – meaning it ignores 'organic' emissions such as those stemming from forest fires, plus other human-caused contributions – but it’s prone to under-reporting or other errors, which China has shown recently.

Carbon-monitoring satellites, on the other hand – which are already used by Japan and the US – allow for far greater precision, directly tracking carbon dioxide levels in Earth’s atmosphere over both land and water and registering CO2 movements in the air.